Stabilized Thin Lens

ABSTRACT

A thin ophthalmic lens stabilized through incorporation of flange around all or a portion of a perimeter of the thin lens.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 14/809,093 filed Jul. 24, 2015 entitled StabilizedThin Lens, which claims benefit of and priority to ProvisionalApplication Ser. No. 62/029,355 filed Jul. 25, 2014 entitled StabilizedThin Lens, both of which are hereby incorporated herein by reference intheir entireties.

FIELD OF THE INVENTION

The present application relates to optical lenses and, moreparticularly, molded optical lenses formed with a stabilizing featurethat prevents warping of the lens after formation.

BACKGROUND OF THE INVENTION

Relatively thin, optical lenses, such as lenses ranging from 0.5millimeters to 3.0 millimeters in thickness, are common in the marketplace, however, there are several challenges to the production of suchlenses. For example, in certain circumstances, relatively thin,polymeric optical lenses tend to warp or otherwise lose their intendedform when removed from the lens mold in which they were formed.

This problem is exacerbated in the case of thin, polarized, polymericoptical lenses. Polarized optical lenses are commonly produced byincorporating an absorptive polarizer formed by stretching a sheet of,for example, polyvinyl alcohol having iodine doping, into or on a baselens substrate. When a thin polymeric lens incorporating such apolarizer is removed from the lens mold, the stretched sheet attempts toregain its un-stretch form and thereby pulls and deforms the formed lensout of the lens's intended shape. This deformation can result in a lenshaving a “potato chip-like” or “saddle” shape. Lenses exhibiting suchdeformation are typically not acceptable in the market place. FIG. 1A isan example of such a deformed molded lens and FIG. 1B is an example of anon-deformed molded lens.

In order to overcome this problem, manufactures may attempt to cool themolded lenses within the mold for increased amounts of time in the hopeof achieving increased lens stability at decreased temperatures.However, this technique has the obvious disadvantage of decreasingthroughput of lens production.

What is needed in the art is a more effective means for stabilizing themolded form of a thin, polymeric lens after molding that does not impactproduction throughput.

SUMMARY OF THE INVENTION

The present invention provides an effective means for stabilizing a thinpolymeric lens such that, after molding or formation, the thin polymericlens will maintain the intended molded form and/or geometry. Thisobjective is achieved through the formation of a flange around all or aportion of a perimeter of the thin lens.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, referencebeing made to the accompanying drawings, in which:

FIG. 1A is a perspective view of a deformed thin molded lens.

FIG. 1B is a perspective view of a non-deformed thin molded lens.

FIG. 2A is a perspective view of a flanged, thin, molded lens accordingto one embodiment of the present invention.

FIG. 2B is a perspective view of three flanged, thin, molded lensesaccording to one embodiment of the present invention.

FIG. 3 is a plan view of a pair of flanged, thin, molded lensesaccording to one embodiment of the present invention.

FIG. 4 is a side elevation view of a flanged, thin, molded lensaccording to one embodiment of the present invention.

FIG. 5 is a perspective view of a pair of flanged, thin, molded lensesaccording to one embodiment of the present invention.

DETAILED DESCRIPTION

Specific embodiments of the invention will now be described withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the embodimentsillustrated in the accompanying drawings is not intended to be limitingof the invention. In the drawings, like numbers refer to like elements.

The present invention provides an effective means for stabilizing a thinpolymeric lens such that, after molding or formation, the thin polymericlens will maintain the intended molded form or geometry. With referenceto FIGS. 2A through 5 , these objectives are, in part, achieved bymolding the thin polymeric lens 10 such that the lens is formed with astabilizing rim or flange 12 around the perimeter 14 of the molded lens10.

The present invention is not limited by the polymeric material employedto form the thin lens 10. The polymeric substrate or material may be athermoset material or a thermoplastic material. With respect tothermoset materials, the substrate may include polymers from diethyleneglycol bis (allyl carbonate) or diallyl diglycol carbonate, such asCR-39® from PPG, or Akzo Nobel brands NS205, NS200 and NS207. The lenssubstrate may also comprise other thermoset materials such as polymersof 1,3 butylene glycol dimethacrylate, acrylonitrile, allylmethacrylate, ethoxymethyl methacrylate, ethylene glycol dimethacrylate,polyethylene glycol dimethacrylate; ally esters; co-polymers of allylesters with styrene or vinyl type monomers, such as diallyl maleate,diallyl phthalate, methallyl methacrylate, and high index copolymerscontaining, e.g., vinyl functionality, isocyanates, urethanes,sulfur-containing aromatic vinyl compounds, and bromine-containingaromatic acrylic compounds.

With respect to thermoplastic materials, the substrate may comprisepolycarbonate resin such as that sold by Teijin, Sabic, and Bayer, Inc.of Pittsburgh, Pa. under various tradenames. The lens substrate may alsocomprise other thermoplastic materials such as polyamides, polystyrenes,polysulphones, mixtures of polycarbonate and polyurethanes, polyesters,polysulfones, polystyrenes, amorphous polyolefins, and acrylics.

In certain embodiments of the present invention, as shown in FIG. 2A,the lens 10 is tinted or colored by including a dye or tinting agentwithin the lens substrate.

In certain embodiments of the present invention, the lens 10 is formedwith a functional film or laminate incorporated within or on a frontsurface 16 or a back surface 18 of the thin lens 10. In certainembodiments, the functional laminate or film is incorporated solelywithin the perimeter 14 of the thin lens 10 and is not incorporated intothe area of the flange 12. Alternatively, in certain embodiments, thefunctional laminate or film is incorporated within the area of the thinlens 10 as well as within all or a portion of the area of the flange 12.The functional attributes of the functional laminate may include, forexample, tinting or coloration, anti-reflection, anti-fogging, hardcoating, polarization, photochromism, and easy-cleaning.

In certain embodiments of the present invention, the thin lens 10 has anapproximately uniform thickness between the front surface 16 and backsurface 18 of 0.8 to 2.5 millimeters. In certain other embodiments ofthe present invention, the thin lens 10 has a non-uniform thicknessbetween the front surface 16 and back surface 18 that ranges fromapproximately 0.8 to 2.5 millimeters.

In certain embodiments, the thin lens 10 of the present invention has acircular perimeter 14. The present invention is not limited by adiameter 20 of the thin lens 10. In certain embodiments, the diameter 20of the thin lens 10 is approximately 65 to 85 millimeters. In certainembodiments, the diameter 20 of the thin lens 10 is approximately 75millimeters.

In certain embodiments of the present invention, the flange 12 is formeduniformly or symmetrically around the perimeter 14 of the thin lens 10.For example, if the thin lens 10 has a circular form or perimeter 14,the flange 12 may also have a circular perimeter 22. In certainembodiments, a width of the flange 12 from the lens perimeter 14 to aperimeter 20 of the flange 12 is approximately 5 to 20 millimeters. Forexample, in the case of a thin lens 10 having a circular form and adiameter 20 of 75 millimeters and a symmetrical flange 12 having adiameter of 87.9 millimeters attached thereto, a width of the flange 12would be approximately 12.9 millimeters.

Alternatively, in certain embodiments, the flange 12 is formedasymmetrically around the perimeter 14 of the lens 10. Alternativelystated, the width of the flange 12 from the lens perimeter 14 to aperimeter 20 of the flange 12 is not substantially constant and isvariable.

In certain embodiments of the present invention, the flange has athickness between a back surface 24 of the flange 12 and a front surface26 of the flange 12 of approximately 0.5 to 3 millimeters. In certainembodiments, the thickness of the flange 12 will be less than athickness of the lens 10 at perimeter 14. In certain embodiments, thethickness of the flange 12 will be greater than a thickness of the lens10 at perimeter 14.

In certain embodiments of the present invention, the entire flange 12 ispositioned within a plane that is the same as or parallel to a plane inwhich the lens 10 resides or the same as or parallel to a plane thatrepresents a best fit plane through the lens 10. Alternatively, incertain embodiments of the present invention, the flange 12 is in adifferent, non-parallel plane than the plane in which the lens 10resides or a different, non-parallel plane than a plane that representsa best fit plane through the lens 10.

In certain embodiments of the present invention, the interface orattachment point of the perimeter 14 of the lens 10 and the flange 12forms a non-zero degree angle.

The flange 12 is formed, for example, during molding or casting of thelens 10 in a flanged or flangeless mold or cast set-up. The flange 12may be formed of the same material or substrate as the lens 10, forexample the flange 12 may be formed of polycarbonate. Alternatively, incertain embodiments of the present invention, the flange 12 is formed ofa different material than that used to form the thin lens 10.

In practice, the flange 12 may be removed from the molded lens duringprocessing of the thin lens 10. Alternatively, the thin lens 10 may beprocess without removing the flange 12. This may advantageously assistin protecting and maintaining the geometry of the thin lens 10 up to thepoint that the lens 10 associated with a lens frame of other structurethat may assist in maintaining the geometry of the thin lens 10.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. A stabilized ophthalmic thin lens comprising: athin lens having a perimeter; and a flange extending from the perimeter.2. The stabilized thin lens of claim 1 wherein the thin lens has athickness of 0.8 to 2.5 millimeters.
 3. The stabilized thin lens ofclaim 1 wherein the thin lens substrate comprises a dye.
 4. Thestabilized thin lens of claim 1 wherein the thin lens comprises afunctional film.
 5. The stabilized thin lens of claim 1 wherein theflange has a width of 5 to 15 millimeters.
 6. The stabilized thin lensof claim 1 wherein a thickness of the thin less is greater than athickness of the flange.
 7. The stabilized thin lens of claim 1 whereinthe flange is formed symmetrically about the thin lens.
 8. A stabilizedophthalmic thin lens comprising: a round, unfinished thin lens; and around flange extending out ward from a perimeter of the thin lens. 9.The stabilized thin lens of claim 8 wherein the thin lens has athickness of 0.8 to 2.5 millimeters.
 10. The stabilized thin lens ofclaim 8 wherein a best fit plane formed through the thin lens isparallel to a plane defined by the flange.
 11. The stabilized thin lensof claim 8 wherein the thin lens comprises a functional film.
 12. Thestabilized thin lens of claim 8 wherein the thin lens comprises a dye.13. The stabilized thin lens of claim 8 wherein a thickness of the thinlens is greater than a thickness of the flange.
 14. The stabilized thinlens of claim 8 wherein the flange is formed symmetrically about thethin lens.
 15. A method for stabilizing a thin lens comprising: forminga thin lens having a perimeter; and forming a flange extending from theperimeter.
 16. The method of claim 15 wherein the step of forming a thinlens having a perimeter comprises forming a thin lens by injectionmolding.
 17. The method of claim 15 wherein the step of forming a thinlens having a perimeter comprises forming a thin lens that has athickness of 0.8 to 2.5 millimeters.
 18. The method of claim 15 whereinthe step of forming a thin lens having a perimeter comprises forming athin lens comprising a functional laminate.
 19. The method of claim 15wherein the step of forming a flange extending from the perimetercomprises forming a flange having a thickness that is less than athickness of the thin lens.
 20. The method of claim 15 wherein the stepof forming a flange extending from the perimeter comprises forming aflange having a width of 5 to 15 millimeters.